High density polyethylene/wood flour composite: Optimization of processing temperature, processing time and coupling agent concentration

Wood plastic composites (WPCs) consisting of high density polyethylene (HDPE) reinforced with high-loading (55 wt%) of wood flour (WF) were fabricated with melt-blending technique. In this compounding method, processing parameters such as different mixing temperatures (of 165, 180 and 195°C), mixing times (of 5, 10 and 15 minutes) and coupling agent contents (of 2 and 4 wt%) were evaluated. Prepared specimens were analyzed with tensile, Izod, shore D, DMTA, short-term creep, DSC, TGA, water absorption and water contact angle characterizations. Results revealed that mixing temperature of 180°C, mixing time of 10 minutes and coupling agent concentration of 4 wt% were found as the best processing conditions. The mentioned conditions provided enhanced dispersion of WF particles within the HDPE matrix, due to optimum viscosity of the polymer melt and effective residence time of compound in the mixer, and beside them efficient interfacial adhesion between WF and polymer matrix.